Larger factories were equipped to make finished buttons. Button factories were located in the Illinois River towns of Beardstown, Meredosia, Naples, Pearl, and Kampsville, Illinois, and in Washington and Muscatine, Iowa, on the Mississippi River.

In the factories, the shells were sorted by type and size and soaked in vats of water. When a button cutter needed more shells, he would take a bucketful from the vats. One man operated each cutting machine
, such as the machine from the Boyd Button Company (1926-1948) in Meredosia, Illinois. The machine consisted of a hollow drill bit (hollow cylindrical saw) held by a key pushed into a drill valve. The operator held the mussel shell in place with leather mitts or shell tongs while he drilled out the plugs or blanks.

Small pressurized streams of water sprayed onto the shell as it was cut. This damped down the dust and cooled the saw, which still had to be sharpened by hand with a three-sided rasp,
the teeth alternately filed in and out, after every few cuts.
Each shell produced from three to twenty button blanks. The blanks pushed one another through the hollow drill bit and out the back end, where they were caught in a container.

After drilling, the plugs were sanded and planed down into the nacre discs called blanks. The blanks were hauled to a finishing department or separate plant such as the Muscatine Button Factory in Iowa.

Once weekly, after he had worked perhaps ten hours a day for five and a half days, each man's blanks were graded for quality and weighed to calculate his piecework salary (one cent per ligne thickness of blank, cut to specifications only). The salary was $7.00 to $20.00 per week.

Finishing
The next step was finishing, which was usually done by women. Each blank was polished
on a four-to-six-inch wide emery wheel and machine-drilled with (an optional) fish-eye groove and two holes or with four holes or a shank hole.
The finishers graded, sized, weighed, and boxed the finished buttons
to sell in bulk to clothing manufacturers. Women sewed buttons on cards (at home, joined in the work by children) or in a factory that had special sewing machines, at the pay rate of one cent per card. These cards were sold to retail outlets.